Since I upgraded to ver. 0.9.14 I haven't been able to connect my Kindle PW (firmware 5.3.0) to Calibre via USB on my Linux laptop. I have an older version (0.8.something) on a Windows laptop that DOES connect to the PW just fine.

It appears the PW is mounting read-only. WTF? If there is file system damage on the PW wouldn't that show up when mounting on Windows as well?

Devices possibly connected: Kindle 2/3/4/Touch/PaperWhite Device Interface,
Trying to open Kindle 2/3/4/Touch/PaperWhite Device Interface ... failed
Opening of the following devices failed
<calibre.devices.kindle.driver.KINDLE2 object at 0x9d74b2c>
Traceback (most recent call last):
File "site-packages/calibre/devices/__init__.py", line 157, in debug
File "site-packages/calibre/devices/usbms/device.py", line 862, in open
File "site-packages/calibre/devices/usbms/device.py", line 640, in open_linux
File "site-packages/calibre/devices/usbms/device.py", line 676, in filter_read_only_mount_points
DeviceError: The main memory of KINDLE2 is read only. This usually happens because of file system errors.

Did the sudo fsck.vfat -y /dev/sdb1 thing but it didn't fix the problem. At least it told me where the corruption was. I was able to mount the PW on a Windows box and do a Disk Check there. The corrupt files were in .Trash-1000, so I deleted that whole thing and now Calibre connects to it. YAY! I was so afraid I'd have to reset the PW and reload all my books.